Altera Corporation
2–201
October 2007
Stratix II GX Device Handbook, Volume 2
Stratix II GX Transceiver Architecture Overview
CPRI Specification V2.1 defines the following three line rates for
deployment flexibility:
■
CPRI line bit rate option 1: 614.4 Mbps
■
CPRI line bit rate option 2: 1228.8 Mbps (2 x 614.4 Mbps)
■
CPRI line bit rate option 3: 2457.6 Mbps (4 x 614.4 Mbps)
Stratix II GX transceivers support all three line bit rate options.
Figure 2–149
shows the ALT2GXB transceiver data path when configured
in CPRI mode.
Figure 2–149. ALT2GXB Transceiver Data Path in CPRI Mode
Table 2–47
shows ALT2GXB configurations supported by the
Stratix II GX transceivers in CPRI mode.
Transmitter Digital Logic
Receiver Digital Logic
Analog Receiver and
Transmitter Logic
FPGA
Logic
Array
TX Phase
Compensation
FIFO
RX Phase
Compen-
sation
FIFO
Byte
Serializer
8B/10B
Encoder
Serializer
Clock
Recovery
Unit
Word
Aligner
Deskew
FIFO
8B/10B
Decoder
Byte
De-
serializer
Byte
Ordering
Rate
Match
FIFO
De-
serializer
Table 2–47. ALT2GXB Configurations in CPRI Mode
Data Rate
(Mbps)
REFCLK Frequencies (MHz)
Channel Width
614
61.4, 76.675, 122.8, 153.5
8 bit
1228
61.4, 76.675, 122.8, 153.5, 245.6, 307
8 bit
2456
61.4, 76.675, 122.8, 153.5, 245.6, 307,
491.2, 614
8 bit